staging: vc04_services: Remove explicit NULL comparison

Replace explicit NULL comparison with ! operator to
simplify code.

Found with Coccinelle script:
@@
expression ptr;
position p;
statement s0, s1;
@@

ptr@p =
\(kmalloc\|devm_kzalloc\|kmalloc_array\|devm_ioremap\|usb_alloc_urb\|
alloc_netdev\|dev_alloc_skb\)(...)
... when != ptr

if (
(
+ !
ptr
- == NULL
)
) s0 else s1
Signed-off-by: Gargi Sharma <gs051095@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c

@@ -1590,7 +1590,7 @@ dump_phys_mem(void *virt_addr, u32 num_bytes)
 	num_pages = DIV_ROUND_UP(offset + num_bytes, PAGE_SIZE);
 
 	pages = kmalloc(sizeof(struct page *) * num_pages, GFP_KERNEL);
-	if (pages == NULL) {
+	if (!pages) {
 		vchiq_log_error(vchiq_arm_log_level,
 			"Unable to allocation memory for %d pages\n",
 			num_pages);